i am getting 3 analog signals at the inputs of ADC0808 and i am displaying it on LCD. they are voltage current and temperature signals. the problem is that when i vary one of the analog input it also effects the data from other inputs. that is if i vary voltage it resutls in the variation of voltage data, current data and temprature data on tha Screen of LCD. i tried my best to isolate it from each other by putting delays and clearing the arrays and data memory locations but the problem is as it is... please help me to rectify my problem...

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Been there, done that. Connect one input to ground and switch the mux to that input before reading any of your other inputs. This will eliminate the crosscoupling between channels in most cases. The "proper" way to do it is to drive each input with an active low impedance source which will discharge the input capacitance of the ADC, most people however just connect passive sources to ADC inputs.